The present invention relates generally to raster displays, and more particularly, to a means by which a graphics image may be generated on a raster display, such as a liquid crystal display device.
Liquid crystal display devices are used for a number of different applications in several different industries. For example, in the aircraft industry, liquid crystal displays are used for flight instruments such as altitude direction indicators and horizontal situation indicators. It is desirable to form a graphical image on the screen of a display as quickly as possible. For example, a military aircraft operating at high speeds, and capable of a broad range of maneuvers, requires a rapidly changeable graphics display to constantly provide the pilot with current information related to the orientation of the aircraft at any given instant in flight. A display that is relatively slow to respond could potentially have dangerous consequences for a pilot. Therefore, a need exists to provide a high speed graphics screen fill of a liquid crystal display that is capable of instantaneous change in response to information received from sensors monitoring the aircraft orientation.
The present invention has been designed to provide a raster display, such as a liquid crystal display, capable of changing a graphics image in just a few milliseconds. The high speed graphics fill of the present invention is accomplished by use of a graphics processor and memory means in association with the graphics processor.
It has been known to use a "seed fill" technique which draws the graphics image in an individual pixel-by-pixel approach. Under the method of the present invention, the graphics image is drawn using a line-by-line approach which results in a much faster response time. The present invention incorporates look-up tables into the memory means associated with the graphics processor for shortening the time the processor requires to compute mathematical relationships for creating the graphical image.